1. Field of the Invention
The present invention relates to a ventilation member and a ventilation structure.
2. Description of Related Art
Air-permeable membranes need to be attached to housings for ECU boxes, electrical double layer capacitors, aluminum electrolytic capacitors, etc. to control the internal pressures of the housings. An example of a technique for attaching an air-permeable membrane to a housing is to weld the air-permeable membrane to the housing. However, this technique can only be applied to housings made of thermoplastic resins. In addition, this technique may cause damage of air-permeable membranes during welding.
In the case where a housing is made of a thermosetting resin unsuitable for welding, for example, a technique of bonding an air-permeable membrane to the housing with a double-sided adhesive tape is used. A technique of attaching a snap-fit part to the housing is also used, as disclosed in JP 2004-047425 A, for example. However, the former technique may cause the double-sided adhesive tape to peel off from the housing, which raises concerns about safety. The latter technique has a drawback in that the shape of the housing needs to be conformed to the snap-fit part.
JP 2010-062094 A and JP 2010-247547 A propose ventilation members in which air-permeable membranes are less susceptible to deformation when the ventilation members are attached to housings. In each of these ventilation members, two metal bodies serving as support bodies are used and the metal bodies are fixed to each other so as to sandwich an air-permeable membrane therebetween. Ventilation members having this configuration require neither welding nor bonding of air-permeable membranes to support bodies, and can also be attached to housings made of thermosetting resins by insert molding. However, the ventilation members having this configuration require further improvements to suppress the deformation of the air-permeable membranes when the ventilation members are attached to the housings and further to increase the reliability by being firmly connected to the housings.